Impact of premenopausal status at breast cancer diagnosis in women entered on the placebo-controlled NCIC CTG MA17 trial of extended adjuvant letrozole
- 1 February 2013
- journal article
- research article
- Published by Elsevier BV in Annals Of Oncology
- Vol. 24 (2), 355-361
- https://doi.org/10.1093/annonc/mds330
Abstract
MA17 showed improved outcomes in postmenopausal women given extended letrozole (LET) after completing 5 years of adjuvant tamoxifen. Exploratory subgroup analyses of disease-free survival (DFS), distant DFS (DDFS), overall survival (OS), toxic effects and quality of life (QOL) in MA17 were performed based on menopausal status at breast cancer diagnosis. At diagnosis, 877 women were premenopausal and 4289 were postmenopausal. Extended LET was significantly better than placebo (PLAC) in DFS for premenopausal [hazard ratio (HR) = 0.26, 95% confidence interval (CI) 0.13-0.55; P = 0.0003] and postmenopausal women (HR = 0.67; 95% CI 0.51-0.89; P = 0.006), with greater DFS benefit in those premenopausal (interaction P = 0.03). In adjusted post-unblinding analysis, those who switched from PLAC to LET improved DDFS in premenopausal (HR = 0.15; 95% CI 0.03-0.79; P = 0.02) and postmenopausal women (HR = 0.45; 95% CI 0.22-0.94; P = 0.03). Extended LET after 5 years of tamoxifen was effective in pre- and postmenopausal women at diagnosis, and significantly better in those premenopausal. Women premenopausal at diagnosis should be considered for extended adjuvant therapy with LET if menopausal after completing tamoxifen.Keywords
Funding Information
- Canadian Cancer Society through National Cancer Institute of Canada (10362))
- National Cancer Institute in the United States (CA31946, CA21115, CA25224, CA38926, CA32102))
This publication has 20 references indexed in Scilit:
- Longer-Term Outcomes of Letrozole Versus Placebo After 5 Years of Tamoxifen in the NCIC CTG MA.17 Trial: Analyses Adjusting for Treatment CrossoverJournal of Clinical Oncology, 2012
- Late Extended Adjuvant Treatment With Letrozole Improves Outcome in Women With Early-Stage Breast Cancer Who Complete 5 Years of TamoxifenJournal of Clinical Oncology, 2008
- Summary of aromatase inhibitor trials: The past and futureThe Journal of Steroid Biochemistry and Molecular Biology, 2007
- Efficacy of Letrozole Extended Adjuvant Therapy According to Estrogen Receptor and Progesterone Receptor Status of the Primary Tumor: National Cancer Institute of Canada Clinical Trials Group MA.17Journal of Clinical Oncology, 2007
- Assessment of Quality of Life in MA.17: A Randomized, Placebo-Controlled Trial of Letrozole After 5 Years of Tamoxifen in Postmenopausal WomenJournal of Clinical Oncology, 2005
- Randomized Trial of Letrozole Following Tamoxifen as Extended Adjuvant Therapy in Receptor-Positive Breast Cancer: Updated Findings from NCIC CTG MA.17JNCI Journal of the National Cancer Institute, 2005
- Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomised trialsThe Lancet, 2005
- Five Versus More Than Five Years of Tamoxifen for Lymph Node-Negative Breast Cancer: Updated Findings From the National Surgical Adjuvant Breast and Bowel Project B-14 Randomized TrialJNCI Journal of the National Cancer Institute, 2001
- Five Versus More Than Five Years of Tamoxifen Therapy for Breast Cancer Patients With Negative Lymph Nodes and Estrogen Receptor-Positive TumorsJNCI Journal of the National Cancer Institute, 1996
- Randomised comparison of 5 years of adjuvant tamoxifen with continuous therapy for operable breast cancerBritish Journal of Cancer, 1996